Surface maintenance machine

ABSTRACT

A SURFACE MAINTENANCE MACHINE USING A TOOL SUCH AS A BRUSH, AND HAVING A FIRST VACUUM BLOWER FOR RECEIVING DUST AND DEBRIS FROM THE BRUSH, AND HAVING A SEPARATE VACUUM BLOWER FOR REMOTE USE WITH A HAND HELD CLEANING WAND. ELECTRICAL SWITCHING AND AIR VALVING CONTROLS ARE OPERATED FROM A SINGLE HAND CONTROL SO THAT ALTERNATELY THE BRUSH AND ITS ASSOCIATED VACUUM BLOWER WILL   BE DRIVEN FROM A SINGLE MOTOR AND WHEN THE CONTROL IS IN ANOTHER POSITION THE BRUSH AND ITS ASSOCIATED VACUUM BLOWER WILL NOT BE POWER DRIVEN FROM THE MOTOR, BUT THE MOTOR WILL DRIVE THE SECOND VACUUM BLOWER FOR USE WITH THE HAND HELD WAND.

June 29, 1971 KRlER ETAL 3,588,945

SURFACE MAINTENANCE MACHINE Filed June 13, 1969 3 Sheets-Sheet 1 FIE: 4

INV/SN'IURS.

KITH M KRIER DONALD J HAUB June 29, 1971 K N. KRIER ETAL 3,588,945

SURFACE MAINTENANCE momma Filed June 13, 1969 3 Sheets-Sheet 2 OFF INVIL'N'IURS KEITH A) KE ueoum-o -l HAM? J/WF United States Patent O 3,588,945 SURFACE MAINTENANCE MACHINE Keith N. Krier, Minneapolis, and Donald J. Haub,

Champlin Township, Minn, assignors to Tennant Company, Minneapolis, Minn.

Filed June 13, 1969, Ser. No. 832,926 Int. Cl. A471 5/28 U.S. (ll. 15-332 12 Claims ABSTRACT OF THE DISCLOSURE A surface maintenance machine using a tool such as a brush, and having a first vacuum blower for receiving dust and debris from the brush, and having a separate vacuum blower for remote use with a hand held cleaning wand. Electrical switching and air valving controls are operated from a single hand control so that alternately the brush and its associated vacuum blower will be driven from a single motor, and when the control is in another position the brush and its associated vacuum blower will not be power driven from the motor, but the motor will drive the second vacuum blower for use with the hand held \wand.

BACKGROUND OF THE INVENTION (1) Field of the invention The present invention relates to floor maintenance machines which have a vacuum source and provide for the use of a hand held wand with means to selectively direct vacuum to the machine or to the wand.

(2) Prior art In relatively high power floor maintenance machines which use a brush and vacuum for cleaning, the use of remote wands has been desired. Various machines which use wands as well as a brush have been advanced, but these usually use a single vacuum source and the floor brush continues to rotate while the wand is in use. The machine usually remains stationary while the wand is being used. When the brush is running during the stationary operation, a streak or floor burn can appear where the brush contacts the surface.

Where only one source of vacuum is used, some arrangement has to be made to direct the vacuum from the brush housing to the wand, and these are usually mechanically complex.

In the present device a separate source of vacuum is used for hand held wands, and by operating a single control handle, the brush is controlled so that it is not powered when the wand is being used, and also separate sources of vacuum are driven for the brush and for the wand at the desired time.

SUMMARY OF THE INVENTION This invention relates to improvements in machines for maintaining a surface, especially carpeted floor areas. A novel valve and switching arrangement is provided to facilitate both cleaning and vacuuming by machine action or by hand held wand or cleaning tool. When cleaning with the wand, the main brush does not rotate. This prevents the occurrence of a cleaning mark or burn on the carpet or surface being maintained because the machine is usually stationary during wand use. The apparatus accomplishes a cleaning job with one path operation, covering large areas and yet is able to clean restricted areas by means of the hand held wand.

High volumes of air are provided for the brush operation through the use of a separate large vacuum blower, which is different from the blower used for the hand held wand. The flexible skirt in front of the housing for the brush serves as a deflector for particles that may be thrown forwardly by the brush during operation, and the sides of the machine or brush housing remain spaced from the surface or open thus providing access for the movement of high volumes of air into the brush chamber.

The machine remains level with the surface being cleaned by virtue of a three-wheeled or tricycle type support. The front support wheel is actually a roller that is centrally located and is elliptical in cross section along its axis (not unlike a football with the ends cut off). This elliptical longitudinal or axial cross sectional shape allows the operator to maneuver the machine over a surface of carpeting, pivoting and turning, yet keeping the brush in contact with the carpet. The roller can be slid endwise along the carpet, or can roll in a forwardly direction as desired.

Non-marking wheels are rotatably mounted about vertical axes and provide protective means to keep the machine spaced from side walls. These wheels are rotated about substantially upright axes so that they will roll along a side wall when the machine comes in close to the wall, but will keep the machine spaced so that the walls will not be marked up.

The brush as shown in the present invention has a herringbone pattern of bristles. The herringbone is arranged so that the center of the V formed on the brush is aligned with the vacuum opening, and the rows of bristles are arranged so that particles of debris will be moved along the V toward the vacuum opening, and also air will be moved by the rotating brush toward the vacuum opening so that the air flow is aided by this V shaped brush bristle pattern.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a floor maintenance machine made according to the present invention with parts in section and parts broken away;

FIG. 2 is an exploded schematic view showing the components of the machine for obtaining operation of a remote hand held wand and also of the brush and vacuum system associated with the brush;

FIG. 3 is a sectional view taken as on line 33 in FIG. 1;

FIG. 4 is a sectional view taken as on line 44 in FIG. 3;

FIG. 5 is a front elevational view of the machine of FIG. 1;

FIG. 6 is a fragmentary enlarged sectional view taken forwardly of the view of FIG. 3 showing switch actuating lever positions; and

FIG. 7 is a schematic electrical diagram of the control circuit of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, there is shown a floor maintenance machine designated generally 10 which includes a frame or housing 11, supported upon rear wheels 12 that are spaced apart at opposite rear corners of the machine, and a single front roller assembly 13 centrally located at the front of the machine to give three-point support for the machine housing. The machine is provided with a rotatable cylindrical surface maintenance tool comprising a brush 14. The frame and drive area of the machine is basically identical to the apparatus covered by US. Pat. No. 2,862,224, issued Dec. 2, 1958. The frame has handles for permitting an operator to move the machine over the surface to be conditioned. Only one handle is shown for clarity.

The frame housing, as shown, comprises a peripheral flange 15 which extends all the way around the frame, and has a suitable internal partition flange 16 shown in 3 dotted lines in the drawing and in section and schematically in FIG. 2. This partition flange 16 forms, in cooperation with the peripheral flanges 15, a brush chamber that extends laterally across the machine and in Which the brush 14 is rotatably mounted.

Each of the rear wheels 12 is journalled for rotation about its axis, and one of these wheels 12 is adapted to be leveled, or in other words is adjustably mounted in a suitable manner to level the frame 11. The front roller assembly 13 is shown in front view in FIG. 5, and in side view in FIG. 1 and comprises a bracket 18 which is fixed to the peripheral flange 15 at the front of the machine, and as shown is generally an inverted U-shape. The side legs of the bracket 18 are cut at an angle rearwardly and a second inverted U-shaped bracket 19 having parallel side legs is used for rotatably mounting a roller 20. The roller 20 is rotatably mounted on suitable pins between and to the legs of bracket 19. The second bracket 19 is movably attached to the first bracket 18 with suitable parallel links or arms '21 that are pivotally mounted onto the side members of the bracket 18 and also pivotally mounted onto the side members of the bracket 19. As shown, the lower one of the links 21 is actually pivotally mounted right at the axis of rotation of the roller 20 between the side legs of bracket 19. A tubular hand Wheel nut 22 is rotatably mounted with a suitable integral member 23 to the top wall of the bracket 18, and a screw 24 is fixedly mounted to the top wall of the bracket 19. This screw 24 is threadably attached to the hand wheel nut 22 so that the nut 22 can be rotated and the bracket 19 threadably moved toward or away from the bracket 18. The bracket 19 and roller 20 will be moved up and down as guided by the links 21 when the tubular nut 22 is rotated. This then will determine the height of the lower edge 25 of the peripheral flange 15 above the carpet or surface 26 that is being maintained. Thus, the height adjustment for the brush 14 is obtained by turning the nut 22 through the use of the hand wheel. The roller 20 is centrally located in respect to the transverse direction of the brush, and is the sole support for the forward portions of the frame. The frame is supported on the rear wheels 12, which are spaced apart in opposite corners of the machine in the lateral direction and by the centrally located front roller 20.

A first vacuum fan or blower assembly 30 is mounted on a suitable bracket 31 to the frame 11 of the machine. This vacuum fan or blower 30 includes a rotor or impeller 32, and an outer housing 33 in which the rotor rotates. When the rotor is rotating, air is blown or exhausted out through an exhaust neck 34 of the fan housing, and a vacuum is created at the axis of the rotor and air is pulled in through a duct 35. The duct 35 connects through suitable hose means 36 to a vacuum port 37 that is defined in a wall of the housing 11 and opens to the brush chamber defined in the frame or housing. Thus, when the vacuum fan 30 is working, vacuum is present at this port 37 and air flows through the hose 36 to the fan, and then air is exhausted out through the duct 34.

The rotor 32 which may be any suitable or preferred construction, comprises as shown an impeller having a disc and radial vanes or blades. The rotor is constructed so that air is taken in through the central portions and exhausted by the rotor out through the duct portions 34 of the housing. The rotor is mounted onto an assembly 40 which comprises a known one-Way clutch member. The assembly 40 may be a one-way bearing-clutch as sembly such as Model RCB101416 made by the Torrington Company, Torrington, Conn. Clutch assembly 40 is mounted onto a drive shaft 41 and the outer portion or hub of the one-way clutch. The clutch will drive between the drive shaft 41 which is suitably rotatably mounted in the blower housing, and the rotor, only when the shaft 41 is rotating in direction as indicated by the arrow 42. When the shaft 41 rotates in opposite direction, the rotor is not driven but free wheels. The rotor will not turn in this opposite direction because of air resistance. Suitable one-way clutch means can be connected between a separate shaft for the vacuum blower and the drive shaft, rather than mounting the rotor right on the clutch, if desire An electric motor 45 is suitably mounted onto the machine 10. The motor comprises power means and is of the capacitor start type which can be reversed by reversing connections to the starting winding. The motor has a double ended output or drive shaft shown at 46. At a first end, a pulley or sheave 47 is drivably mounted onto the shaft 46 and this sheave in turn drives a belt 48 which drives a sheave 49 that in turn is drivably mounted onto the shaft 41. In normal operation, the shaft 41 is much shorter than that shown schematically in FIG. 2, and can be supported by the bearings actually in the vacuum fan housing 33. If desired, suitable outboard hearings or supports can be provided for shaft 41.

At the opposite end of the motor output or drive shaft, a sheave 50 is drivably mounted onto the shaft 46, and this sheave 50 has a belt 51 drivably mounted thereover. The belt 51 in turn drivably engages a sheave 52. Sheave 52 is mounted onto a one-way clutch-bearing hub assembly 53. The inner part of the one-way clutch-bearing hub is drivably mounted onto a shaft 54 for the brush 14. The one-way clutch assembly is made so that when the sheave 52 drives in direction as indicated by the arrow 55, the one-way clutch assembly 53 will engage, and shaft 54 will be rotated in this direction. The separate arrow 56 is shown by the brush to show that this is the direction of rotation of the brush. However, if the sheave 52 rotates in opposite direction from that indicated by arrow 55, the one-way clutch assembly 53 will merely free wheel or in other words will rotate without driving the shaft 54. Then the brush will not be powered or will not be rotated in this opposite direction.

At the outer end of shaft 41, there is a one-way clutch assembly 60. The inner part of the clutch assembly 60 is drivably mounted onto the shaft 41, and the clutch forms a one-way driving connection to a sheave 61. A belt 62 is drivably mounted onto the sheave 61, and the belt in turn drives the sheave 63. The sheave 63 is drivably mounted onto a rotor shaft 64 of a second vacuum blower assembly 65 of usual design. The vacuum blower assembly 65 has an internal rotor so that air will be taken in through the center through a connection for a hose 66 and will be discharged out through the discharge throat 67 when the rotor is rotated in direction as indicated by the arrow 68. It should be noted, that the one-way clutch assembly 60 is made so that it will free wheel or will not drive sheave 61 when the shaft is rotating in direction as indicated by the arrow 42. Thus, when shaft 41 is driving the rotor 32, the sheave 60 will not be driven, and the rotor for the vacuum blower 65 will not be driven either. However, if the shaft 41 rotates in opposite direction, then rotor 32 will not be driven, but sheave 61, and the rotor for the vacuum blower 65 will be driven causing vacuum to be present at the hose 66 and air to be discharged out through the throat 67.

The throat 67 is connected through a suitable flexible hose shown at 70 to a manifold 71. The throat 34 is also connected to this manifold 71. A large filter bag 72 is mounted onto the outer end of the manifold 71, and is in turn mounted in a suitable manner onto the frame of the machine 10. Air coming through the manifold 71 Will enter the filter bag and be discharged out through the walls, but the filter bag will filter out dust and debris carried by the air into the manifold.

The filter bag can be of suitable construction as shown in the aforementioned Pat. No. 2,862,224.

The manifold 71 has a divider wall 73. The divider wall 73 has a first opening 74 leading from the throat or duct 34 into the filter bag, as shown perhaps best in FIG. 4, and a second opening 75 which leads from the flexible hose 70 into the filter bag. A flexible flap 76 is mounted along one side as at 77, and is of size so that when it is flat against the wall 73, it will cover the first opening 74. This flap is made of suitable resilient material, such as a fabric strengthened rubber, and forms a flapper type valve. The air movement through throat 74 moves the flapper valve 76 to a dotted position as shown in FIG. 4, when it is unrestricted.

A control lever 80 is used for controlling the machine. The control lever has a leg 81 that is mounted for rotation in the walls defining the manifold 71, and extends through the wall. At the end of the control lever which protrudes into the area opening to the filter bag 72 there is an arm 82 that is drivably mounted on the leg. The arm 82 extends downwardly from the leg 81 of the control lever 80 (see FIG. 3) and has a disc like poppet valve 83 mounted at the lower portion thereof. In FIG. 3, the control lever 80 is shown in a centered or off position. The control lever can be moved to a position wherein the poppet valve 83 covers the opening 75, and prevents air from escaping out of the manifold through the opening 75 into the tube 70 when there is a greater than atmospheric pressure in the bag 72. Also, the control lever 80 can be moved to a second position wherein the poppet valve will be over the flapper valve 76, and resting against the flapper valve 76 substantially in position overlying the opening 74. These positions are shown in dotted lines in FIG. 4. Also, the position of the control lever is shown in dotted lines in FIGS. 2 and 6.

The motor 45 is of a capacitor start type which can be reversed by reversing the connection between the starting windings 103 and the power source.

A motor control switch assembly is mounted in a switch box 84, and a control handle location plate 85 is mounted over the switch box. The location plate has three notches defined therein as shown in FIG. 2, and a first center notch 86 is used for an off position and holds the control handle 80 as shown in FIGS. 3 and 4. In this position the motor 45 is not powered at all, and the unit is shut off. In the first working position notch 87, which is labeled brush and shown in dotted lines in FIG. 2, the control handle, when in this position, will be positioned to power the motor 45 so that the shaft 41 will rotate in the first direction as indicated by arrow 42, and the sheave 52 will rotate in direction indicated by the arrow 55 and thereby drive the brush in direction as indicated by arrow 56. The poppet valve 83 will be covering the opening 75 when the control handle 80 is in the brush position or in other words in slot 87, and the poppet valve vw'll be up against the wall 73 because of the depth of the slot.

When the control handle 80 is placed into a second operative slot 88, the control handle will actuate switches to reverse the direction of motor 45, so that the shaft 41 will rotate in opposite direction from arrow 42, and will drive the sheave '61 through the one-way clutch 60 to drive the second vacuum blower 65 in directions indicated by the arrow 68 causing vacuum to be applied through the tube or hose 66, and air to be exhausted into the filter bag through opening 75. The valve 83 will then be in its position over the opening 74 and holding the flapper valve 76 closed against the wall 73. The first vacuum blower 30 will not be energized at all, and neither will the brush 14 be rotated because the one-way clutch 53 will be slipping (the sheave 52 will be turning in opposite direction from arrow 55) and the one-way clutch 40 will also be slipping because the shaft 41 will be turning in opposite directions from arrow 42. However, there will be vacuum on the hose 66 which will be applied to .a hand tool or wand indicated generally at 89 in FIG. 1.

The switch box 84 houses two switches illustrated schematically in FIG. 7 as switches 93 and 94. Switch 93 is a single pole-single throw switch. The switch 93 is positioned on the bottom of the box, and has an actuator lever 95 protruding therefrom with a roller 96 at the outer end thereof.

The control lever 80 has an actuator plate 97 fixedly attached thereto and positioned to be aligned generally with the arms and rollers of the switches 93 and 94. The switch 94 has an actuator arm 100 extending therefrom and a roller 10]. which extends outwardly out of the switch box, and aligns with the roller 96 of the lower switch 93.

When the control lever is in the center notch 86 in the olf position, it is pulled far enough back, as shown in FIG. 4, so the rollers 96 and 101 of both switches are not contacted by the plate 97, and the switches are in their normal position as shown in solid lines in FIG. 7. Then the unit is shut off, and the circuit from its power source is open, as shown in FIG. 7. An ordinary plug is used for connecting the unit to its power source. This is just an alternating current power source.

When the device is in its wand position which is shown in solid lines in FIG. 6, the actuator plate 97 is also in position as shown in solid lines. The slot 88 for the wand position is long enough so that the actuator plate 97 slides forwardly and contacts the roller 96 for the switch 93 and closes it. You will note that the actuator plate 97 clears the roller 101 in this position so that the switch 94 remains in its solid line position. However, the switch 93 moves to its dotted position, and power is supplied to the motor 45 so that the motor will rotate in a first direction. In this position, the motor rotates in direction as indicated as indicated by the arrow 102 in FIG. 2, shown on the motor, and this will cause the shaft 41 to rotate in opposite direction from arrow 42, and in turn will drive the vacuum blower 65 so that vacuum is supplied to the wand 89, and air is exhausted out through the opening into the filter bag 72, and this air is then filtered, and the wand can be used for remote cleaning with vacuum.

When the control lever is moved to its brush position so that the control lever nests in the slot 87, the lever is in the dotted position as shown in FIG. 6, and the actuator plate 97 is also in its dotted position. Then the plate 97 will contact both rollers 101 and 96 and both switch 93 and switch 94 will be moved to their dotted position (FIG. 7). As can be seen, this will reverse the connections to the starting winding 103 of motor 45, reversing the direction of drive of the motor 45 so that the shaft 41 will be rotated in the direction as indicated by arrow 42, driving the rotor 32 for vacuum blower 30, and supplying vacuum to the housing for the brush 14. At the same time, the one-way clutch 53 will drive from sheave 52 to the shaft 54 rotating the brush in direction as indicated by the arrow 56. Then the unit will be set for cleaning surfaces as it moves forwardly over the surface.

Air will be drawn in underneath the peripheral flange 15 along the sides of the housing. The forward part of the housing is covered by a flexible strip 105 (one or more) which extends from the peripheral flange 15 down to the surface, as shown in FIGS. 1 and 5. The strip 105 prevents a substantial air flow in through the forward edge of the housing, but the air will flow in through the sides at the ends of the brush. As the brush is rotated, air will then flow in under the housing and out through the port 37 into the duct 35, and out through the duct 34 to the manifold 71. In the brush position the flapper valve 76 will be free to move to its dotted position as shown in FIG. 4, and the poppet valve 83 will be in the dotted position covering the opening 75 to prevent air from going out through the hose 70. It should be noted that in its dotted position, the flapper valve 76 serves as a deflector for debris picked up by the brush and being discharged into the filter bag. This valve deflects any sharp objects and helps to protect the interior of the filter bag 72 so that it will not be damaged by these objects. Thus, the flexible flapper valve serves not only to shut off reverse flow through the opening 74 when the wand is being used, but also to deflect sharp objects to prolong the life of the filter bag.

Again, when the control lever is put in the center off position in the shallow slot 86 the plate 97 is with- 7 drawn sufiiciently far so neither roller 101 nor 96 are contacted and the unit will be shut off entirely.

The brush 14 has its bristles arranged in a herringbone or V-shaped pattern as shown in FIG. 2. The V-shape causes a general movement of particles in toward the center of the apex of the V shown at 106, and this apex can align substantially with the center of the port 37, so that debris will move inwardly toward this apex and will be picked up more easily by the vacuum and carried into the port 37, out through the vacuum blower and into the filter bag. Also, air currents will be generated generally inwardly toward the center of this V because of the herringbone or V-shaped rows of bristles. When the brush is rotating as indicated by arrow 56, the movement of air under the sides of the housing and axially along the brush is enhanced by this Y-shaped herringbone bristle configuration. The apex 106 can be aligned with the vacuum outlet, so that air will flow more easily into the port 37, and aid in the cleaning job.

Thus, by providing for control switches for reversing the motor 45, and one-way clutches to the brush and its associated vacuum blower arranged so that the brush and its associated vacuum blower are both driven when the motor rotates in a first direction, and are not drive when the motor rotates in a second direction permits the brush and its associated vacuum blower to be operated at the same time, and then upon reversal of the motor disengage. When the motor is reversed, a one-way clutch is provided to drive a second blower which is not driven when the brush and its associated vacuum blower are a driven. By disengaging the brush and its associated vacuum blower when the second vacuum blower for the hand held wand is driven, floor burns or streaks caused by the brush standing in one spot are eliminated, and all of the power can be directed toward the wand operation. The manifold portion is such that the reversing of the motor and the blocking off of the appropriate port in the manifold is done with the same control lever. Also, the herringbone design on the brush cooperates to enhance vacuum or air flow from the sides or ends of the brush into alignment with the vacuum port discharging into the blower for the brush housing.

The brush is rotated so the bristles move opposite to the normal direction of travel of the machine where the bristles contact the carpet. This greatly aids in cleaning ability and insures one pass cleaning. Debris laying on the carpeting which is not picked up when the brush first contacts it will be blocked ahead of the brush and will again be contacted by the brush until it is picked up.

The forward roller 20 can be slid in endways direction because of its elliptical shape and will not catch on carpeting and the like, and the three point support insures that the housing will maintain its spacing from the floor being cleaned at all times. The front roller can be adjusted so that proper contact of the bristles of the brush 14 can be made with the carpeting or other surfaces to be cleaned. The roller does not require the space necessary for a caster wheel, thus allowing the machine to get closer to a wall. Also, the roller gives a large bearing surface for easy manipulation on carpeted surfaces. The flexible flapper valve 76 is attached only on one side of the opening 74 so that it will act like a flapper and cause deflection of debris coming in through the opening 74, but will move back to cover the opening 74 when air comes in through opening '75. The poppet valve 83 will ride over the flapper to hold it against the opening 74 and prevent reverse flow of air out through opening 74 and into blower 30 when the wand is being used. All of the one-way clutch assemblies can be of the type previously described.

In order to protect the walls of a room where the machine is working guide wheels can be used. Non-marking wheels 110 are rotatably mounted on brackets 111 (only one shown) about a vertical axis. The bracket 131 is fixed to the housing 11 and the wheel 1 10 protrudes out 8 beyond the side of the machine a small distance so the wheel will engage the wall and prevent the machine from bumping and marking the wall. There normally are two such wheels used, one adjacent the front of the machine and one adjacent the rear of the machine.

What is claimed is:

1. A surface maintenance machine comprising a frame, a chamber defined in said frame, a powered floor maintenance tool mounted in said chamber, a first vacuum source mounted on said frame, means to connect the first vacuum source to the chamber, a second vacuum source mounted on said frame, power means, first drive means to connect said power means to power said first vacuum source and said tool simultaneously when said power means rotates in a first direction, and to disengage the power means from said first vacuum source and said tool when said power means rotates in a second direction, and second drive means connecting said second vacuum source and said power means to power said second vacuum source only when said power means rotates in said second direction.

2. The floor maintenance machine of claim 1 wherein said first and second vacuum sources comprise first and second rotary blowers each having air exhaust duct means, the air exhaust duct means from both of said vacuum blowers discharging into a common mainfold, said power means comprising an electric motor, a control handle, switch means operatively connected between said control handle and said motor, valve means in the manifold controlled by said control handle, whereby when said control handle is in a first position it engages said switch means to cause said motor to operate in a first direction and said valve means is moved to open the air outlet from said first vacuum blower and operatively close the air outlet from said second vacuum blower, and when said control handle is in a second position said switch means is moved to change the connection to said motor to cause said motor to rotate in said second direction, and said valve means is moved to close the outlet from said first vacuum blower and to open the outlet from said second vacuum blower.

3. The combination as specified in claim 2 wherein said second vacuum blower means has a vacuum inlet, a flexible hose attached to said vacuum inlet, and a hand held tool at the outer end of said flexible hose.

4. The combination as specified in claim 1 wherein said floor maintenance tool comprises a rotary brush having rows of bristles, said rows of bristles being arranged on the periphery of said brush to form a V-shaped pattern with respect to the rotational axis thereof, the apex of said V-shaped pattern substantially aligning with the vacuum inlet to said chamber.

5. The combination as specified in claim 4 wherein said V-shaped pattern is positioned so that as said brush rotates the debris carried by said brush tends to be moved toward said apex of said V-shaped pattern.

6. The combination as specified in claim 1 and wheel means for supporting said frame, said wheel means com prising a pair of spaced apart wheels at the rear of said frame, and a single roller centrally located at the forward portions of said frame, said roller comprising an elliptical shape in longitudinal cross section, said elliptical shaped roller having rounded portions at opposite ends thereof.

7. The combination as specified in claim 1 wherein said first and second vacuum sources comprise rotating vacuum blowers and said tool is a rotary brush, and said first drive means comprises one-way clutch means operative to drive said vacuum blower and said brush in a first direction only and to free wheel in a second direction.

8. The combination as specified in claim 7 wherein said second drive means comprises one-way clutch means operative to drive said second vacuum blower in a second direction only.

9. A surface maintenance machine comprising a frame, a chamber defined on said frame, a cylindrical rotating brush in said chamber, a first rotatable vacuum blower on said frame, said first blower being connected to withdraw air from said chamber, a second vacuum blower on said frame, means to connect a hand vacuum tool to said second blower, a reversible motor, first drive means including first one-way clutch means to drivably rotate said first vacuum blower and said brush only when said motor rotates in a first direction, and second drive means including second one-way clutch means to drivably rotate said second blower only when said motor rotates in a second direction, and power and control means to select the direction of rotation of said motor.

10. The combination as specified in claim 9 and a manifold, said first and second blowers having separate discharge openings for discharging air through said manifold, a filter bag open to said manifold to filter air exhausted through said manifold, and flapper valve means covering at least one of said openings and being attached along one side only to permit said flapper valve means to deflect away from its associated opening at an acute angle when the blower associated therewith is operating, whereby particles of debris blown through its associated opening will be deflected by said flapper valve means.

11. The combination as specified in claim 9 wherein said first and second blowers have outlets, and said control means includes valve means to cover the outlets of one of the blowers only when the other blower is rotating, and said control means including means to simultaneously 10 change the direction of rotation of the motor and the position of the valve means.

12. The combination as specified in claim 9 and a manifold having a wall defining an opening, and wherein said first vacuum blower discharges air through an opening in said wall a flapper valve covering said opening on a side thereof opposite from said vacuum blower, said flapper valve comprising a thin layer of flexible material, means to fasten said flapper valve to the wall adjacent one side only of said opening, said flapper valve being adapted to deflect outwardly from said Opening at an acute angle with respect to the general plane of said opening to thereby deflect material passing through said opening and permit air to pass from the blower through said opening.

References Cited UNITED STATES PATENTS 1,782,064 11/1930 Gray 15-DIG, 8 2,040,188 5/1936 Smellie 15-366 2,140,143 12/1938 Sellers et al. 15-332 2,751,773 6/1956 Woodson 6823.7

WALTER A. SCHEEL, Primary Examiner C. K. MOORE, Assistant Examiner U.S. Cl. X.R. 

